Minimax LQ stochastic tracking and servo problems

It is proved that the separation between feedback and feedforward of the two-degree-of-freedom linear quadratic (LQ) stochastic controller reported by E. Mosca and G. Zappa (ibid., vol.34, p.240-2, 1989) can be suitably extended, when a linear controller is postulated, to the minimax LQ stochastic tracking and servo problems. Besides the relevance of the results, the authors show that in some problems the Wiener and the H/sub infinity / approaches can play a fruitful complementary role.<
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